I spy ..... Lichen!

Tried looking for something different today although my walk was round one of my favourite wee lochs on the outskirts of East Kilbride. My sister blipped the herons but I decided .... NO birds today ..... they'll still be there tomorrow! The lichen growing, almost covering some of the trees caught my eye. Sadly, I have no idea what type of lichen it is - a google search showed dozens and dozens of different examples - I'll just stick with LICHEN.